1. Field of the Invention
The invention pertains to spacer frame channel that is installed between glass plates along the periphery of a sealed insulating glass unit, more specifically to hermetically sealing the corners of the frame.
2. Description of the Prior Art
The prior art is replete with designs for sealing corners of a spacer frame.
In a spacer frame made from channel stock, a series of V cutout pairs are made on each side of a flat strip for forming a corner in the spacer frame when the strip is roll formed into a channel and the channel is bent on a transverse axis that passes through the apexes of the V-cuts to make the corner. The transverse axis is generally perpendicular to the length or longitudinal axis of the channel. The pairs of V-cuts are spaced from one another along the length of the channel so that each transverse axis is the bend axis for making a corner of the spacer frame.
The V-cut angle is made at 90 degrees so that when the channel is bent on the transverse axis through the apexes, the edges of the V abut parallel against one another. The edges are sometimes welded together. Sealant is applied over the abutting joint outside the joint on the outside of the channel, and in some applications additionally over the abutting joint outside the joint on the inside of the channel. In another prior art design, the V-cut angle is made at less than 90 degrees so that the edges overlap and can be spot welded or bonded. And then sealant is placed over the bonded edges.
U.S. Pat. No. 3,994,109 patented Nov. 30, 1976 by R. Pandell describes hollow straight rails which are miter cut under an angle of 45 degrees and joined so that the inclined surfaces of the cuts abut each other to form a corner of a spacer frame. Legs of an angular plastic insert or connecting member holds the rails together at the corner. The outer corner of the connecting member is angled to form a chamber with the inner wall of the rail. Sealant is injected through a hole in the spacer frame to fill the chamber which seals the corner. A second hole may be provided that faces one of the window panes for controlling filling of the chamber, indicating the chamber is full when the sealant is pressed against the pane.
U.S. Pat. No. 5,255,481 patented Oct. 26, 1993 by Misera et al., describes a spacer channel in which front and back sides of the channel have inward folds so that the apexes of the inward folds are at the bend axis of the strip for making the corner. Sealant is applied to the outside of the spacer frame at the corner of the frame to fill in the space between the fold crease and the glass.
It is one object of the invention to provide a spacer frame that can be coated continuously on the outside with sealant including over the V cutout at the transverse bend axis for the corner of the spacer frame before the strip is bent or folded, to make the corner.
It is another object of the invention to provide spacer frame channel that moves sealant into the corner joint when bent to make the corner of the frame.
A spacer frame for separating window panes to form an insulated window, having a front first wall, a back second wall spaced from the first wall, and the first wall forming a corner of the frame, comprises a slot through the first wall at the corner extending from the apex of the corner toward the inside of the frame, and first sealant on the first wall, extending into the slot.
A third wall connected to and substantially normal to the first wall has a bend that forms the corner, and includes a second sealant on the third wall between the first wall and the second wall, that extends through the slot in contact with the first sealant.
Another spacer frame of the invention has a front first wall, a back second wall spaced from the first wall, the first wall forming a corner of the frame, the spacer frame including a slot through the first wall at the corner extending from the apex of the corner toward the inside of the frame, the slot being open to an angle of at least 4 degrees.
A method of sealing a spacer frame corner includes applying sealant across an angled cutout on a first wall of the channel of the frame, the cutout having an apex substantially at the axis of bend of the channel for forming the corner of the frame, applying the sealant before bending the channel to make the corner of the frame.